Aptamers are short (20–70 bases) single stranded oligonucleotides (ssRNA/ssDNA) which bind to their targets through 3D conformational complementarities with high af?nity and speci?city. The term aptamer is derived from a Latin word “aptus” with the meaning of “to ?x”, indicating the lock and key relationship of aptamers for their targets. Aptamers can be tailored selected against various targets including nucleotides, amino acids, proteins, small molecules, virus and live cells; proteins are the major targets in aptamer research.
Aptamers can be selected through an in vitro process called Systematic Evolution of Ligands by Exponential enrichment (SELEX), which was ?rstly developed by three groups independently in 1990. Compared to monoclonal antibodies, aptamers possess similar af?nity and speci?city, but have minimal immunogenicity, high production, low cost and high stability, making them the most advanced reagents for detection and inhibition of target molecules beyond monoclonal antibodies. Till now, there have been over 900 aptamers developed against various targets for diagnostic and therapeutic purposes. For therapeutic applications, aptamers have been developed against a broad spectrum of diseases, including AIDS, cancer, diabetes, skeletal diseases. There are 11 aptamers under different stages of clinical trials for treatment of macular degeneration, cancer, coagulation and in?ammation. Pegaptanib, an aptamer against vascular endothelial growth factor (VEGF), the ?rst therapeutic aptamer approved by the FDA for the treatment of wet age-related macular degeneration (wet AMD), has been successfully used in market. It opens a wide window for the following development of more therapeutic oligonucleotide aptamers.
Despite great promise and significant efforts in aptamer development over the past 20 years, it is troublesome that only one aptamer has been approved for use in the market. There are some bottlenecks which limit the development and applications of aptamers, including the high failure rate of the traditional SELEX, low serum stability and high clearance rate in vivo, poor understood of the interaction mechanism to the target and so on. Fortunately, more and more researchers have been joined to address these issues. For example, various optimizations on the traditional SELEX have been performed to avoid the failure of SELEX; various chemical modification strategies have been employed to increase the serum stability and extend the circulation time in vivo; structural studies have been performed to understand the molecular insight between aptamers and their targets. These studies could facilitate the development of aptamer-based basic research as well as translation for applications.
Specific sub-topics of this article collection on aptamers include:
Aptamer Selection
• SELEX optimization
• Automatic selection technologies
• High-throughput selection of aptamers
• Fast selection of aptamers
Aptamer Characterization
• Analytical technologies for aptamers
• Modifications of aptamers
• Pharmacodynamics & pharmacokinetics of aptamers
Molecular Insight
• 3D structure determination of aptamers and their targets
• Computational modeling of aptamers
• Artificial Intelligence (AI) in aptamer research
Aptamer theranostics
• Aptamers for diagnostics
• Aptamers for therapeutics
• Aptamer-based drug discovery
Aptamers are short (20–70 bases) single stranded oligonucleotides (ssRNA/ssDNA) which bind to their targets through 3D conformational complementarities with high af?nity and speci?city. The term aptamer is derived from a Latin word “aptus” with the meaning of “to ?x”, indicating the lock and key relationship of aptamers for their targets. Aptamers can be tailored selected against various targets including nucleotides, amino acids, proteins, small molecules, virus and live cells; proteins are the major targets in aptamer research.
Aptamers can be selected through an in vitro process called Systematic Evolution of Ligands by Exponential enrichment (SELEX), which was ?rstly developed by three groups independently in 1990. Compared to monoclonal antibodies, aptamers possess similar af?nity and speci?city, but have minimal immunogenicity, high production, low cost and high stability, making them the most advanced reagents for detection and inhibition of target molecules beyond monoclonal antibodies. Till now, there have been over 900 aptamers developed against various targets for diagnostic and therapeutic purposes. For therapeutic applications, aptamers have been developed against a broad spectrum of diseases, including AIDS, cancer, diabetes, skeletal diseases. There are 11 aptamers under different stages of clinical trials for treatment of macular degeneration, cancer, coagulation and in?ammation. Pegaptanib, an aptamer against vascular endothelial growth factor (VEGF), the ?rst therapeutic aptamer approved by the FDA for the treatment of wet age-related macular degeneration (wet AMD), has been successfully used in market. It opens a wide window for the following development of more therapeutic oligonucleotide aptamers.
Despite great promise and significant efforts in aptamer development over the past 20 years, it is troublesome that only one aptamer has been approved for use in the market. There are some bottlenecks which limit the development and applications of aptamers, including the high failure rate of the traditional SELEX, low serum stability and high clearance rate in vivo, poor understood of the interaction mechanism to the target and so on. Fortunately, more and more researchers have been joined to address these issues. For example, various optimizations on the traditional SELEX have been performed to avoid the failure of SELEX; various chemical modification strategies have been employed to increase the serum stability and extend the circulation time in vivo; structural studies have been performed to understand the molecular insight between aptamers and their targets. These studies could facilitate the development of aptamer-based basic research as well as translation for applications.
Specific sub-topics of this article collection on aptamers include:
Aptamer Selection
• SELEX optimization
• Automatic selection technologies
• High-throughput selection of aptamers
• Fast selection of aptamers
Aptamer Characterization
• Analytical technologies for aptamers
• Modifications of aptamers
• Pharmacodynamics & pharmacokinetics of aptamers
Molecular Insight
• 3D structure determination of aptamers and their targets
• Computational modeling of aptamers
• Artificial Intelligence (AI) in aptamer research
Aptamer theranostics
• Aptamers for diagnostics
• Aptamers for therapeutics
• Aptamer-based drug discovery